SMOG FAILED- High NOx '94 gle

Post by **[email protected]** » Wed Sep 17, 2008 10:01 am

Hi guyz, I just smogged my car that was recovered from theft after 10 months.

it failed here's the result---------------------------------------------------------------------speed - %CO2 ! %O2 ! HC ! CO% ! NO---------------------------------------------------------------------15mph - 14.9 ! 0.0 ! 15 ! 0.02 ! 698---------------------------------------------------------------------

25mph - 14.9 ! 0.0 ! 6 ! 0.01 ! 858 ---------------------------------------------------------------------

i am guessing its the egr ports. but i have posted asking about cleaning egr b4 but got no replies. giving it another shot.

Also if any body think about other possibilities for high NOx please help me.And if somebody know any short cuts to lower NOx a little bit (enough) to pass smog please let me know.

thanks for reading

Post by **Rev_D21** » Wed Sep 17, 2008 1:52 pm

The EGR sits just behind the intake manifold, visible when looking at the engine from the front. If you can get the exhaust tube that feeds the EGR off and the 2 nuts that hold it to the intake manifold you should be able to spray it out with brake cleaner. NOx forms when cylinder temps are too high and can be link to a malfunctioning EGR valve. One way to test this is to stick your fingers under the EGR valve and press the internal disc upwards. If the engine goes to stall then the valve is not stuck.

Post by **[email protected]** » Wed Sep 17, 2008 4:10 pm

Reverend D wrote:The EGR sits just behind the intake manifold, visible when looking at the engine from the front. If you can get the exhaust tube that feeds the EGR off and the 2 nuts that hold it to the intake manifold you should be able to spray it out with brake cleaner. NOx forms when cylinder temps are too high and can be link to a malfunctioning EGR valve. One way to test this is to stick your fingers under the EGR valve and press the internal disc upwards. If the engine goes to stall then the valve is not stuck.

can u put a picture that shows the location of the egr ports and valve. thank you

Post by **Rev_D21** » Mon Sep 22, 2008 9:27 am

I wish I could but I no longer have my Alty. Can anyone get this guy a pic of the EGR?

Post by **[email protected]** » Wed Sep 24, 2008 9:22 am

hi, i tested the Egr valve as u said. when i pushed from underneath it thus opening the valve , the engine suddenly dropped rpms and almost instatntly was normal again. does that the mean the egr valve is good. also i removed the egr valve to see whether it was clogged but it was good. i want to know where the egr ports are so i can check them and clean them. i have done it on an accord before but that was rite on top of the intake manifold and was easy. but i can't recognise the egr ports on my altima. is it behind the engine where we cannot see it by just looking from the top.

what is the tube that comes to the egr valve doing. is it a vaccum tube to that creates a vaccum to open the egr valve. where does the exaust gas enter the intake manifold.

Post by **Rev_D21** » Wed Sep 24, 2008 3:21 pm

Looking at the front of the car...you should see a metal tube that runs from the side of the exhaust manifold to underneath the distributor then disappear. That is the EGR feed tube. To control the EGR Nissan uses a vacuum valve that sits on top of the EGR itself. By pressing the bottom part of the valved you confirmed the valve itself is not clogged. But there could still be an electronic control or vacuum problem present. Can you back probe the plug on the EGR to check for voltage?

Post by **[email protected]** » Wed Oct 01, 2008 11:01 am

hi

i got busy and didn't get time to look at the car until yesterday. i was inspecting the hoses that are around the egr valve and found that the small hose that is connected under the bpt valve was broken and leaking. what are the consequenses of that. will that be a reason for the egr to not work.thanks

Post by **3Q Jay** » Thu Oct 02, 2008 7:00 pm

ah, you are studying and now know the diff b/n an egr and a bpt. very good.the bpt 'thick' hose gets low pressure from the egr feed that revd described, which inb turn allows the bpt to 'pass' the vac signal onto the egr.

odds are good you found the problem, but i would replace all those hoses to be sure. you can check to see that the egr valve is functioning by putting your finger on the underside of the egr as you did before, but just feel--don't press.then with engine warm at ~1800 rpm, you should feel the egr valve pulsing.

still don't know that your intake manifold passages are clean, but getting closer.

Post by **[email protected]** » Thu Oct 02, 2008 9:48 pm

i was also having idliling problems. could that hose be the reason for that too. also how can i check the intake manifold passages and clean if necessary. the smog station guy told that it could be easy and cheap to do and it can also go upto $300 if the passage is clogged deep within in which case they will have to remove the manifold and sent it to a machine shop to heat it and get the build ups melted out. could those people be trying to rip me off or are they genuine. i didn't want to give up the money before other avenues are exausted and the chance to learn is utilized.

Post by **[email protected]** » Fri Oct 03, 2008 12:00 pm

today i put everything back and started the car. i pressed the diaphgram of the egr valve like before, then the car stalled. when i did this before replacing the hose it did not stall but would almost go to stall and recover. but now when i press it it definitly stalls quickly. i also felt under the diaphgram and raised the engine speed, i felt some pulsations but it definitely did not open all the way like when we press it. i do not know how much rpm it was because i raised the engine speed by pulling at the cable while feeling the diapgram with the other hand.

Post by **ka_altima** » Fri Oct 03, 2008 1:53 pm

does anyone have a stock exhaust manifold for the ka fwd i have a leek so it wont pass smog.......

Post by **3Q Jay** » Fri Oct 03, 2008 6:37 pm

sorry no spares. check a boneyard. i'm still amazed at how many U13s i see around--unfortunately most look neglected nowadays.

Post by **3Q Jay** » Fri Oct 03, 2008 6:41 pm

everything you said souinds correct (pulsing, but only part way, stalling when you pull it wide open). neither egr nor bpt should affect idle.i posted the part numbers for the gaskets you need. get some long thin bottle brushes, use throttle body cleaner liberally, and roto-rooter the intake passage.

Post by **[email protected]** » Sat Oct 04, 2008 4:29 pm

i actually used some long and thick steel wires unwound along with throttle body cleaner to go through the holes under the egr valve and the one behind the distributor in which the exaust gas enters the intake manifold. so do u think i should give it another try at the smog station? or is there anything else i should go over b4 smoging it.

Post by **3Q Jay** » Sat Oct 04, 2008 5:12 pm

from the top of this post, your HC and CO are good. blow all that crap out that you loosened up with the rooter.unless there is roughness at low revs that was NOT there when you did previous smog, then you should do better this time around. your numbers show you had the cats nice and hot last time, just as we discussed. do same this time too.post up your results after this go-round.

Post by **[email protected]** » Mon Oct 20, 2008 2:21 pm

Hi guyz,finally today i got time to smog the car again and it passed.

here is the resultit failed here's the result---------------------------------------------------------------------speed - %CO2 ! %O2 ! HC ! CO% ! NO---------------------------------------------------------------------15mph - 14.9 ! 0.0 ! 16 ! 0.02 ! 362---------------------------------------------------------------------

25mph - 14.9 ! 0.0 ! 11 ! 0.02 ! 385---------------------------------------------------------------------

meanwhile my car got approved for $500 CAP, and when the smog tech heard about it he was insisting that changing that hose or cleaning it would not have fixed the problem and he wanted me to use the CAP money. and the guy told that according to their procedure the car has to go through a pre-test and then if it measures below average values it could go through in certification mode. so basicly i would have lost Atleast $70 even if it passed and $100 if it failed(towards CAP deductible).

Anyway i told him that I will risk the $20 re-test fee and just do the regular re-test without going through CAPS and it passed. When the result came the smog tech had a blank look on his face and he was saying that it defeats the purpose of having the CAP, if people start fixing the car themselves.

Post by **mick** » Mon Sep 28, 2009 11:17 pm

CAP has a low income part on the application and then you would only have a $20 deductible.

SMOG FAILED- High NOx '94 gle

SMOG FAILED- High NOx '94 gle

Re: (Reverend D)

Re: (Reverend D)

Re: (Reverend D)

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Re: (3Q Jay)

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Re: SMOG FAILED- High NOx '94 gle ([email protected])

Re: SMOG FAILED- High NOx '94 gle (ka_altima)

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